There are three basic types of clothes hangers. The first is the wire hanger, which has a simple loop of wire, most often steel, in a flattened triangle shape that continues into a hook at the top. The second is the wooden hanger, which consists of a flat piece of wood cut into a boomerang-like shape with the edges sanded down to prevent damage to the clothing, and a hook, usually of metal, protruding from the point. Some wooden hangers have a rounded bar from tip to tip, forming a flattened triangle. This bar is designed to hang the trousers belonging to the jacket. The third kind and most used in today's world are also plastic coat hangers, which mostly mimic the shape of either a wire or wooden hanger. Plastic coat hangers are also produced in smaller sizes to accommodate the shapes of children's clothes.
Some hangers have clips along the bottom for suspending skirts. Dedicated skirt and trousers hangers may not use the triangular shape at all, instead using just a rod with clips. Specialized pant hanger racks may accommodate many pairs of trousers. Foldable clothes hangers that are designed to be inserted through the collar area for ease of use and the reduction of stretching are an old, yet potentially useful variation on traditional clothes hangers.
Wire is versatile, and wire clothes hangers are cheap. Wire may also be used in combination with wooden or plastic hangers, e.g. as wired trouser bar, or (partly) inserted into the wood or plastic. Other hanger systems optionally using wire are clothes valets, laundry racks and laundry drying racks or wires.
Some metal wired clothes hangers are applied locally with an anti-slip slid over the surface of the metal where the clothes contact the hanger. This may be on the shoulder part for hanging shirts, or the bar part for hanging trousers, or even inside the clips along the bottom of a hanger for suspending skirts.
However, such anti-slip slids are post-fabricated and mounted in a subsequent operation step onto the hangers or hanger systems. This involves a costly subsequent operation in the production process. Moreover said anti-slip slids often do not provide sufficient friction for holding clothes.
On the other hand, applying anti-slip slids in one operation onto a metal wire gives problems of adhesion of the anti-slip slids to said metal surface. Also, when a metal wire is coated with an anti-slip layer, the wire still needs to be mechanically deformed to form a clothes hanger or a paperclip. Problems may arise with fraying said layer or with damaging said layer.
Yet another problem is that the anti-slip coating must be resistant to solvents, like e.g. in the case of solvents used in dry-cleaning.
Yet a major problem is cost-effectiveness. Metal clothes hangers are a very cheap commodity product. Adding an anti-slip coating will have to be very cost-effective.